Summary report for the 2007–2008 STATEMAP Project: Geologic mapping to support improved database development and understanding of urban corridors, critical aquifers, and special areas of environmental concern in Texas

The Geologic Map of the Southeast Part of the Austin, Texas, 30 x 60 Minute Quadrangle: Central Texas Population Corridor Encompassing Bastrop and Smithville, scale 1:100,000, was constructed through digital compilation of eight 1:24,000-scale open-file geologic maps. The map is intended to be used by professionals and laypersons as a source of general geologic information that relates to land and resource use and management. Geology of the area consists mostly of Paleocene through Eocene mud- and sand-rich units. Minor Upper Cretaceous marine marl and calcareous mud deposits are in the western study area. Quaternary high-gravel deposits and well-defined terrace deposits of the Colorado River also occur. Bedrock units typically exhibit eastward regional dips of less than 2°. In the west and east parts of the study area, northeast-striking normal faults cut strata. Aquifer units include the Carrizo-Wilcox, Queen City, and Sparta. Resources include sand, gravel, clay, lignite, and oil.